/**
* find/return a pair for the single character string ch
* precondition ch.length() == 1; ch is a single character string
* @return the coordinates of ch in the encryption matrix
*/
private Point getCoordinates(String ch)
{
int j, k;
for(j=0; j < SIZE; j++)
{
for(k=0; k < SIZE; k++)
{
if (myMatrix[j][k].equals(ch))
{
return new Point(j,k);
}
}
}
return new Point(-1, -1); // should never reach this
}